JP3912247B2 - Tuning fork type resonator element and tuning fork type vibrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tuning fork type vibrating piece and a tuning fork type vibrator including the tuning fork type vibrating piece. In particular, the present invention In-groove electrode and routing electrode The present invention relates to an improvement for avoiding defects such as short circuits.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, tuning fork crystal units that are easy to downsize are known as one type of piezoelectric vibration device. In this type of vibrator, for example, as disclosed in Patent Document 1 below, a predetermined electrode is formed on the surface of a quartz wafer formed into a tuning fork shape by etching using a photolithography technique. The tuning fork type quartz crystal vibrating piece is provided.
[0003]
Patent Document 2 below discloses a configuration in which a groove is formed at the center of the front and back (main surface) of each leg of a tuning fork type crystal vibrating piece. Thus, when the groove part is formed on the front and back surfaces of the leg part, the vibration loss of the leg part is suppressed even if the vibration piece is miniaturized, and the CI value (crystal impedance) can be kept low, which is effective. This type of tuning fork type crystal resonator is particularly suitable for mounting on precision equipment such as a watch.
[0004]
The shape of the electrode formed on the surface of this type of tuning-fork type vibrating piece will be specifically described below.
[0005]
FIG. 9 shows a tuning fork type crystal vibrating piece a provided in a general tuning fork type crystal resonator. The tuning-fork type crystal vibrating piece a includes two legs b and c, and first excitation electrodes d1 and d2 and second excitation electrodes e1 and e2 are formed on the legs b and c, respectively. In FIG. 9, the portions where the excitation electrodes d1, d2, e1, e2 are formed are hatched.
[0006]
Further, in the tuning fork type crystal vibrating piece a, rectangular grooves b2 and c2 are formed on main surfaces b1 and c1 which are front and back surfaces of the leg portions b and c, respectively.
[0007]
And as said 1st excitation electrode, in-groove electrode d1 formed in the inside of the groove part b2 shape | molded in the front and back (main surface) b1 of one leg part b, and the side surface of the other leg part c It is comprised by the side electrode d2 formed in c3, and these are connected by the routing electrode f.
[0008]
Similarly, as the second excitation electrode, the in-groove electrode e1 formed inside the groove c2 formed on the front and back surfaces (main surface) c1 of the other leg c, and the side surface of the one leg b It is comprised by the side electrode e2 formed in b3, and these are connected by the routing electrode g.
[0009]
In addition, the in-groove electrodes d1 and e1 formed inside the respective groove parts b2 and c2 have the entire inside of the groove parts b2 and c2 even if some processing errors occur in the groove parts b2 and c2 and the in-groove electrodes d1 and e1. In the plan view shown in FIG. 9, the area of the in-groove electrodes d1, e1 is set to be slightly larger than the area of the groove portions b2, c2 so that the in-groove electrodes d1, e1 are formed. . Therefore, actually, the in-groove electrodes d1 and e1 are formed from the bottom surface of each of the groove portions b2 and c2 to the vertical wall (the surface in the direction orthogonal to the paper surface of FIG. 9) and the main surfaces b1 and c1. become. For example, when the width dimension (the dimension in the left-right direction in the figure) of each of the leg portions b and c is 200 μm, the wraparound dimension (dimension A in the figure) of the in-groove electrodes d1 and e1 to the main surfaces b1 and c1 is as follows. It is about 10 μm.
[0010]
Further, the side surface electrodes e2 and d2 formed on the side surfaces b3 and c3 slightly wrap around the main surfaces b1 and c1 from the side surfaces b3 and c3 in order to secure a good connection with the routing electrodes f and g. Is formed. For example, when the width dimension of each of the leg portions b and c is 200 μm, the wraparound dimension (dimension B in the drawing) of the side electrodes e2 and d2 to the main surfaces b1 and c1 is about 10 μm.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-294631
[Patent Document 2]
JP 2002-76806 A
[0012]
[Problems to be solved by the invention]
By the way, in order to effectively suppress the CI value in the tuning fork type crystal vibrating piece a described above, it is preferable to secure the opening areas and the depths of the grooves b2 and c2 as large as possible.
[0013]
However, when the opening areas of the grooves b2 and c2 are large and the in-groove electrodes d1 and e1 are formed therein, the in-groove electrode d1 is inevitably routed. g There is concern about these shorts. In particular, an ultra-small crystal resonator (for example, a leg having a width of about 120 μm) that has been developed in recent years is formed on the left leg b in the electrode shape shown in FIG. The in-groove electrode d1 and the routing electrode located inside the leg b (the side close to the right leg c) g and There is a concern about short-circuiting (C portion in FIG. 9). For this reason, in the routing electrode g and the side electrode e2 connected thereto, the wrapping dimension B from the side surface b3 to the main surface b1 must be designed to be small.
[0014]
However, when the wrapping dimension B of the routing electrode g and the side electrode e2 is set to be small, the reliability of the connection state between the routing electrode g and the side electrode e2 is inferior, and in some cases, disconnection occurs. Sometimes it ends up. That is, since these electrodes g and e2 are connected in the vicinity of the inner edge of the leg part b, there is a possibility that the film thickness of the electrode film is not sufficiently obtained at this connection part. If B becomes small, a good connection state cannot be obtained.
[0015]
On the other hand, when it is intended to ensure a large opening area of the groove b2 as described above, the opening edge of the groove b2 is routed around the electrode. g When the inner electrode d1 is formed in the groove b2 using the photolithography technique, the resist solution is formed near the edge of the groove b2 (near the boundary between the groove b2 and the main surface b1). As a result, a resist liquid swell phenomenon occurs due to the influence of the surface tension, and it may be difficult to process the outer edge shape of the in-groove electrode d1 with high accuracy. That is, the processing accuracy of the in-groove electrode d1 is lowered due to the presence of the groove b2. In the situation where the outer edge shape of the in-groove electrode d1 cannot be obtained properly, the wraparound dimension of the in-groove electrode d1 to the main surface b1 cannot be obtained properly, and the in-groove electrode d1 is routed around the C portion. g Contact may cause a short circuit.
[0016]
Thus, in the tuning-fork type crystal vibrating piece a having the legs b and c having the grooves b2 and c2 and the in-groove electrodes d1 and e1 formed therein, the groove b2 and the in-groove electrode d1 are provided. There is a possibility that electrical defects such as short-circuiting or disconnection of electrodes due to the existence may occur. For this reason, in this type of tuning fork type vibrating piece a, further improvement in structure has been demanded.
[0017]
The present invention has been made in view of such points, and an object of the present invention is to provide a tuning fork type crystal vibrating piece and a tuning fork type in which a leg is provided with a groove and an excitation electrode (electrode in the groove) is formed therein. For the vibrator, Between the electrode in the groove and the routing electrode The object is to avoid electrical failures such as short circuits.
[0018]
[Means for Solving the Problems]
-Summary of invention-
In order to achieve the above-described object, the present invention is not limited to the position of the groove formed in the leg or the electrode in the groove in the groove by offsetting the position outward rather than in the center in the width direction of the leg. The electrode is routed Extremely It is possible to avoid contact. In other words, the contact can be avoided by positioning the center position in the width direction of the groove part and the center position in the width direction of the in-groove electrode on the side farther from the vibration center position than the center position in the width direction of the leg part. It should be noted that the CI value is not deteriorated even if the position of the groove and the electrode in the groove is offset to the outside in the width direction of the leg in this way (this is confirmed by a simulation result described later).
[0019]
-Solution-
Specifically, a plurality of legs are provided, a groove is formed on the main surface of each leg, an in-groove electrode is formed inside the groove, and a side electrode is formed on the side of the leg. And the inner electrode in the groove of the leg and the side electrode formed on the side surface located on the inner side of the other leg are connected by the routing electrode extending along the main surface. It is assumed that the tuning-fork type vibration piece is composed. With respect to this tuning fork type vibrating piece, the distance from the center line passing through the center of vibration and extending in the extending direction of the leg portion to the center position in the width direction of the groove portion is defined as the distance from the center line to the center position in the width direction of the leg portion. It is set longer than the distance.
[0020]
For example, when forming an in-groove electrode in a groove using photolithography technology, even if it is difficult to process the outer edge shape of the in-groove electrode with high accuracy due to the influence of the edge of the groove , One In other words, even if the wraparound dimension to the main surface of the in-groove electrode cannot be obtained properly due to the influence of the edge of the groove, the in-groove electrode Pull The occurrence of a short circuit can be avoided by preventing contact with the winding electrode.
[0021]
Other solutions for achieving the above object include the following. That is, the premise is the same tuning fork type vibration piece as the premise according to the above-described solution. Then, with respect to this tuning fork type resonator element, the distance from the center line passing through the vibration center point and extending in the extension direction of the leg portion to the center position in the width direction of the electrode in the groove is defined as the width direction of the leg portion from the center line. It is set longer than the distance to the center position.
[0022]
According to this specific matter, regardless of the formation position of the groove ,groove Inner electrode Pull The occurrence of a short circuit can be avoided by preventing contact with the winding electrode. For this reason, it is not necessary to design a small wraparound dimension from the side surface of the leg portion of the routing electrode or the side electrode connected to the main surface, and it is possible to ensure the reliability of the connection state between the routing electrode and the side electrode. Thus, it is possible to prevent disconnection between the two.
[0023]
Furthermore, it is possible to use each of the above solutions together. That is, with respect to the tuning-fork type resonator element, the distance from the center line passing through the center of vibration and extending in the extending direction of the leg to the center position in the width direction of the groove, and the center position in the width direction of the in-groove electrode from the center line Is set longer than the distance from the center line to the center position in the width direction of the leg. According to this specific matter, it is possible to obtain the effects of each of the above-described solving means, Pull The occurrence of short-circuits can be reliably prevented from coming into contact with the routing electrode, and the reliability of the connection state between the routing electrode and the side electrode can be obtained satisfactorily. Occurrence can be prevented.
[0024]
Further, as shown in the simulation results described later, the CI value is hardly deteriorated even when the positions of the grooves and the electrodes in the grooves are set as described above. That is, it is possible to avoid the short circuit and the disconnection without adversely affecting the vibration characteristics of the tuning fork type resonator element.
[0025]
Moreover, the following are mentioned as a specific shape of the groove part formed in each leg part, and the electrode in a groove | channel. That is, the shape of the groove formed on each main surface is formed symmetrically with respect to the center line that passes through the vibration center point and extends along the extending direction of the leg. Similarly, the shape of the in-groove electrode formed inside each groove is also symmetrical with respect to the center line.
[0026]
According to these specific matters, the vibration characteristics of each leg can be maintained uniformly, so that the above-described short circuit and disconnection can be avoided without adversely affecting the vibration mode of the tuning fork type crystal vibrating piece. become.
[0027]
A tuning-fork type crystal resonator comprising the tuning-fork type vibrating piece according to any one of the above-described solving means and having the tuning-fork type crystal vibrating piece attached in a package is also a technical feature of the present invention. It is a category of thought. In other words, according to this solution, a tuning fork type crystal resonator that has high reliability due to the absence of short-circuiting or disconnection between electrodes and a good CI value that is the effect of forming a groove portion. Can provide.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a case where the present invention is applied to a tuning fork type crystal resonator having two legs will be described.
[0029]
-Description of tuning fork crystal unit-
FIG. 1 is a diagram showing a tuning-fork type crystal vibrating piece 1 provided in a tuning-fork type crystal resonator according to this embodiment. FIG. 2 is a sectional view taken along line II-II in FIG.
[0030]
This tuning fork type crystal vibrating piece 1 includes two legs 11 and 12, and first excitation electrodes 13 a and 13 b and second excitation electrodes 14 a and 14 b are formed on the legs 11 and 12. In FIG. 1, the portions where the excitation electrodes 13a, 13b, 14a, and 14b are formed are hatched.
[0031]
Further, in the tuning fork type crystal vibrating piece 1, rectangular grooves 11 c and 12 c are formed on the main surfaces 11 a and 12 a which are front and back surfaces of the leg portions 11 and 12, respectively. These grooves 11c and 12c have the same shape (width, length, and depth).
[0032]
When the groove portions 11c and 12c are formed on the front and back surfaces of the leg portions 11 and 12 as described above, the vibration loss of the leg portions 11 and 12 is suppressed even if the tuning fork type crystal vibrating piece 1 is reduced in size, and the CI value (crystal impedance ) Is low and effective.
[0033]
And as said 1st excitation electrode, the electrode 13a in a groove | channel formed in the inside of the groove part 11c shape | molded in the front and back (main surface) 11a of one leg part 11, and the side surface of the other leg part 12 The side electrode 13b is formed on 12b, and these are connected by the lead-out electrode 15.
[0034]
Similarly, as the second excitation electrode, the in-groove electrode 14a formed in the groove 12c formed on the front and back surfaces (main surface) 12a of the other leg 12 and the side surface of the one leg 11 are used. The side electrode 14b is formed on 11b, and these are connected by the routing electrode 16.
[0035]
These excitation electrodes 13a, 13b, 14a, and 14b are thin films formed by metal deposition of chromium (Cr) and gold (Au), and the film thickness is set to 2000 mm, for example.
[0036]
In addition, the in-groove electrodes 13a and 14a formed inside the groove portions 11c and 12c have the entire inside of the groove portions 11c and 12c even if some processing errors occur in the groove portions 11c and 12c and the in-groove electrodes 13a and 14a. In the plan view shown in FIG. 1, the area of the in-groove electrodes 13a, 14a is set to be slightly larger than the area of the groove portions 11c, 12c so that the in-groove electrodes 13a, 14a are formed. . Therefore, actually, as shown in FIG. 2, the in-groove electrodes 13a and 14a are formed from the bottom surfaces of the groove portions 11c and 12c to the vertical walls and the main surfaces 11a and 12a. For example, when the width dimension of each of the legs 11 and 12 is 120 μm, the wraparound dimension (dimension A in FIG. 2) of the in-groove electrodes 13a and 14a to the main surfaces 11a and 12a is about 5 μm.
[0037]
Further, the side electrodes 14b and 13b formed on the side surfaces 11b and 12b slightly wrap around the main surfaces 11a and 12a from the side surfaces 11b and 12b in order to secure a good connection with the routing electrodes 15 and 16. Is formed. For example, when the width of the legs 11 and 12 is 120 μm, the wraparound dimension (dimension B in FIG. 2) of the side electrodes 14b and 13b to the main surfaces 11a and 12a is also about 5 μm.
[0038]
The tuning fork type crystal resonator element is configured by mounting the tuning fork type crystal vibrating piece a having such a configuration in a package (not shown).
[0039]
-Explanation of the formation position of the groove and electrode in the groove-
Hereinafter, formation positions of the groove portions 11c and 12c and the in-groove electrodes 13a and 14a, which are characteristic portions of the present embodiment, will be described.
[0040]
As shown in FIG. 1, the groove portions 11c and 12c formed in the main surfaces 11a and 12a of the leg portions 11 and 12 and the formation positions of the in-groove electrodes 13a and 14a are the vibrations of the tuning-fork type crystal vibrating piece 1. Center positions in the width direction of the grooves 11c and 12c (the grooves 11c and 12c) from the center line L passing through the center point (point O in FIG. 1) and extending along the extending direction of the legs 11 and 12 (vertical direction in FIG. 1). Is a distance T1 from the center line L to the center position in the width direction of the legs 11, 12 (the center line of the legs 11, 12 is indicated by a straight line L2). (T1> T). Similarly, a distance T1 from the center line L to the center position in the width direction of the in-groove electrodes 13a, 14a (in this embodiment, the center line of the in-groove electrodes 13a, 14a coincides with the straight line L1) It is set longer than the distance T from the center line L to the center position in the width direction of the legs 11 and 12 (the straight line L2) (T1> T).
[0041]
In other words, as the formation positions of the groove portions 11c, 12c and the in-groove electrodes 13a, 14a, the center position in the width direction of the groove portions 11c, 12c and the center position in the width direction of the in-groove electrodes 13a, 14a are the leg portions 11, 12 is located on the side farther from the vibration center position than the center position in the width direction. Furthermore, in other words, conventionally, the groove portions 11c and 12c and the in-groove electrodes 13a and 14a are formed at the center in the width direction of the main surfaces 11a and 12a of the leg portions 11 and 12, but in this embodiment, the groove portion 11c. 12c and the in-groove electrodes 13a, 14a are formed at positions outside the center position in the width direction of the main surfaces 11a, 12a of the leg portions 11, 12 (outside in the left-right direction in FIG. 1).
[0042]
With this configuration, the inner edges of the grooves 11c and 12c and the inner electrodes 13a and 14a (the edge on the centerline L side of the tuning fork type vibrating piece 1) and the inner edges of the legs 11 and 12 (also the tuning fork type vibrating piece) It is possible to secure a large distance from the center line L side edge of the center electrode L, and the wraparound dimension of the side electrodes 13b and 14b to the main surfaces 11a and 12a and the wraparound electrode 16 to the main surfaces 11a and 12a. The degree of dimensional freedom can be expanded. In the example shown in FIG. 1, the gap between the in-groove electrodes 13a, 14a on the main surfaces 11a, 12a and the side electrodes 13b, 14b formed on the inner side (center line L side of the tuning-fork type vibrating piece 1) is increased. Designed to ensure.
[0043]
On the other hand, the one shown in FIG. 3 ensures a large wraparound dimension of the side electrodes 13b and 14b and the routing electrode 16 to the main surfaces 11a and 12a, and thereby the connection state between the side electrode 14b and the routing electrode 16 is ensured. The reliability is greatly secured so that the occurrence of disconnection can be surely avoided.
[0044]
As described above, in this embodiment, first, the position of the grooves 11c and 12c is offset to the outside in the width direction of the legs 11 and 12, so that the in-groove electrode 13a is placed in the groove 11c using the photolithography technique. Even when a situation in which it is difficult to process the outer edge shape of the in-groove electrode 13a with high accuracy due to the influence of the edge of the groove 11c during formation, the position of the groove 11c is inside By being formed at a position away from the side electrode 14b, there is an influence due to the presence of the edge of the groove 11c. inside It is suppressed to reach the periphery of the side electrode 14b. That is, even if the wraparound dimension of the in-groove electrode 13a to the main surface 11a cannot be appropriately obtained due to the influence of the edge of the groove 11c, the in-groove electrode 13a is inside The contact with the side electrode 14b and the lead-out electrode 16 is suppressed, the occurrence of a short circuit can be avoided, and a highly reliable tuning fork type crystal vibrating piece 1 can be provided.
[0045]
Further, the position of the in-groove electrodes 13a, 14a is offset to the outside in the width direction of the legs 11, 12 so that the positions of the in-groove electrodes 13a, 14a are changed. inside Since it is formed at a position away from the side electrodes 13b, 14b, the in-groove electrode 13 is formed. a is inside Lateral power Pole 1 Contact with 4b and the lead-out electrode 16 is suppressed, and this can also prevent the occurrence of a short circuit. For this reason, it is connected with the routing electrode 16 and it. inside It is not necessary to design the wrapping dimension of the side electrode 14b from the leg side surface 11b to the main surface 11a to be small. inside The reliability of the connection state with the side electrode 14b can be ensured satisfactorily, and the occurrence of disconnection between them can be prevented.
[0046]
Further, when the configuration shown in FIG. 3 is adopted, the side electrodes 13b and 14b and the routing electrode 16 have a large wraparound dimension to the main surfaces 11a and 12a, so that this portion of the electrode is partially removed by milling. It is also possible to finely adjust the vibration characteristics (frequency adjustment, etc.) by further depositing an electrode material on this portion. In the conventional tuning fork type vibrator, milling or vapor deposition is performed only on the electrodes formed near the tips of the legs 11 and 12, that is, the electrodes formed in a relatively large area. However, according to the configuration of FIG. 3, it is possible to expand the area that enables this milling and vapor deposition.
[0047]
Further, as shown in the simulation results described later, even when the positions of the grooves 11c and 12c and the in-groove electrodes 13a and 14a are set as described above, the CI value is hardly deteriorated. That is, it is possible to avoid the short circuit and the disconnection without adversely affecting the vibration characteristics of the tuning fork type resonator element 1. Hereinafter, this simulation will be described.
[0048]
In this simulation, the CI value is calculated for each of the cases where the groove portions 11c and 12c formed in the respective leg portions 11 and 12 of the tuning fork type crystal vibrating piece 1 and the formation positions of the in-groove electrodes 13a and 14a are changed. It is. Further, in this simulation, as shown in FIG. 1, the groove portions 11c and 12c and the in-groove electrodes 13a and 14a were formed in a rectangular shape.
[0049]
In FIG. 4, the position of the in-groove electrodes 13 a, 14 a is positioned at the center in the width direction of the legs 11, 12, and the positions of the grooves 11 c, 12 c are displaced in the width direction of the legs 11, 12. CI values are shown. FIG. 4A shows the simulation results when the width of the grooves 11c and 12c is 53 μm, and FIG. 4B shows the simulation results when the width of the grooves 11c and 12c is 38 μm. The offset value on the horizontal axis in each figure is “0” is the position of the grooves 11c and 12c located in the center in the width direction of the legs 11 and 12, and the “+” side is the legs 11 and 12. Is offset to the outside, and the “−” side is offset to the legs 11 and 12 inside. The offset dimensions are 4 μm and 8 μm, respectively.
[0050]
FIG. 5 shows the case where the positions of the grooves 11c and 12c are positioned at the center in the width direction of the legs 11 and 12, and the positions of the in-groove electrodes 13a and 14a are displaced in the width direction of the legs 11 and 12. Each CI value is shown. FIG. 5A shows a simulation result for the groove portions 11c and 12c having a width of 53 μm, and FIG. 5B shows a simulation result for the groove portions 11c and 12c having a width of 38 μm. Also, the offset value on the horizontal axis in each figure is the same as in FIG.
[0051]
Further, FIG. 6 shows the respective CI values when the positions of the in-groove electrodes 13a and 14a and the positions of the groove portions 11c and 12c are both displaced in the width direction. FIG. 6A shows a simulation result for the groove portions 11c and 12c having a width dimension of 53 μm, and FIG. 6B shows a simulation result for the groove portions 11c and 12c having a width dimension of 38 μm. Also, the offset value on the horizontal axis in each figure is the same as in FIG.
[0052]
Considering the above simulation results, the absolute value of the offset value is larger when the positions of the grooves 11c and 12c and the in-groove electrodes 13a and 14a are offset outward than when they are offset inward. It can be seen that the accompanying deterioration rate of the CI value is small. In particular, FIG. 4 (b), FIG. 5 (a), and FIG. 6 (a) are prominent. In particular, FIG. 4 (b), FIG. 5 (a), and FIG. The CI value hardly deteriorates as the offset value increases. Therefore, it can be seen that there is almost no adverse effect on the vibration characteristics caused by offsetting the positions of the grooves 11c, 12c and the in-groove electrodes 13a, 14a to the outside in the width direction of the legs. That is, according to the configuration of the present embodiment, it has been confirmed that it is possible to avoid an electrical failure such as a short circuit between electrodes without adversely affecting the vibration characteristics. Become.
[0053]
-Modification-
FIG. 7 shows a modification of the shapes of the groove portions 11c and 12c and the in-groove electrodes 13a and 14a. As shown in this figure, in the present example, the base end portions of the legs 11 and 12 can secure a larger wraparound dimension to the main surfaces 11a and 12a of the routing electrode 16 and the side electrodes 14b and 13b. I have to. Therefore, with respect to the base end portions of the leg portions 11 and 12, the formation positions of the groove portions 11c and 12c and the in-groove electrodes 13a and 14a are largely offset outward.
[0054]
In other words, the base end portions of the leg portions 11 and 12 and the other portions have a configuration in which the width dimensions and the outward offset dimensions of the groove portions 11c and 12c and the in-groove electrodes 13a and 14a are different from each other. . In other words, the groove portion 11 extends from the center line L that passes through the vibration center point O and extends along the extending direction of the leg portions 11 and 12. c , 12 c The distance from the center line L to the center position in the width direction of the legs 11 and 12 is longer than the distance from the center line L to the center position in the width direction of the legs 11 and 12. Not only are both set long, but the distance between the base end portions of the legs 11 and 12 and the other portions is different. That is, the base end portion of the leg portions 11 and 12 extends from the center line L to the groove portion 11. c , 12 c The distance from the center in the width direction and the distance from the center line L to the center in the width direction of the in-groove electrodes 13a, 14a are larger than the distances of the portions other than the base end portions of the legs 11, 12 (offset amount). Is set).
[0055]
According to this configuration, the reliability of the connection state between the lead-out electrode 16 and the side electrode 14b can be further ensured, and the occurrence of disconnection between the two can be reliably prevented.
[0056]
In addition, a simulation was performed for the change state of the CI value when the dimension D shown in FIG. The result is shown in FIG. As can be seen from FIG. 8, the CI value hardly deteriorates as the dimension D increases. Therefore, in the configuration of this modification, it is possible to further ensure the reliability of the connection state between the routing electrode 16 and the side electrode 14b without adversely affecting the vibration characteristics. I understand.
[0057]
-Other embodiments-
In the embodiment described above, the offset values of the groove portions 11c and 12c and the in-groove electrodes 13a and 14a are set to be the same. This is because the centers of the in-groove electrodes 13a and 14a are made to coincide with the centers of the groove portions 11c and 12c so that the in-groove electrodes 13a and 14a are formed over the entire interior of the groove portions 11c and 12c. The present invention is not limited to this, and the offset values of the groove portions 11c and 12c and the offset values of the in-groove electrodes 13a and 14a are set to different values, only the groove portions 11c and 12c are offset, or the in-groove electrodes 13a and 14a. May be offset.
[0058]
Further, it is not always necessary to offset the groove portions 11c, 12c and the in-groove electrodes 13a, 14a in both the two leg portions 11, 12, and the groove portions 11c, (12c) of the one leg portion 11, (12) are not necessarily required. ), Only the in-groove electrodes 13a, (14a) of one leg 11, 11 (12), only the grooves 11c, (12c) of the one leg 11, 12 (12) and the in-groove electrodes 13a, (14a) An offset configuration may be used.
[0059]
In the above embodiment, the case where the present invention is applied to the tuning-fork type crystal vibrating piece 1 including the two legs 11 and 12 has been described. However, the present invention is not limited to this, and the three or more legs are used. It is also possible to apply to a tuning-fork type crystal vibrating piece provided with In this case, in a tuning fork type crystal vibrating piece having an even number of legs, all the legs or a pair of legs that are substantially equidistant from the center line of the tuning fork type crystal vibrating piece 1 (the straight line L) described above. The position where the groove and the electrode in the groove are formed is offset with respect to the pair of legs. On the other hand, in a tuning-fork type crystal vibrating piece having an odd number of legs, the positions of the grooves and in-groove electrodes are offset with respect to all or a part of the legs other than the center leg. It will be.
[0060]
Even when the present invention is applied to a tuning-fork type crystal vibrating piece having three or more legs as described above, the offset value of the groove and the offset value of the electrode in the groove are set to different values. Alternatively, only the groove portion may be offset, or only the in-groove electrode may be offset. Furthermore, only the groove part of a part of leg part, only the electrode in a groove | channel of a part of leg part, and the groove part of a part of leg part and the electrode in a groove | channel may be offset.
[0061]
Furthermore, although the case where quartz was used as the piezoelectric material has been described in the above embodiment, the present invention can also be applied to a resonator element using lithium niobate or lithium tantalate.
[0062]
【The invention's effect】
As described above, in the present invention, the distance from the center line passing through the vibration center point and extending along the extending direction of the leg portion to the center position in the width direction of the groove portion is from the center line to the center position in the width direction of the leg portion. It is set longer than the distance. This ,groove Even if the wraparound dimension to the main surface of the electrode in the groove cannot be obtained properly due to the influence of the edge of the groove, the electrode in the groove Pull It is possible to prevent electrical failure such as a short circuit from being prevented from coming into contact with the winding electrode.
[0063]
Further, the distance from the center line passing through the vibration center point and extending in the extending direction of the leg portion to the center position in the width direction of the in-groove electrode is longer than the distance from the center line to the center position in the width direction of the leg portion. It is set. For this reason ,groove Inner electrode Pull It is possible to prevent electrical failure such as a short circuit from being prevented from coming into contact with the winding electrode. As a result, it is not necessary to design the routing electrode or the side electrode connected to it from the leg side surface to the main surface with a small wraparound dimension, and it is possible to ensure good reliability of the connection state between the routing electrode and the side electrode. Thus, electrical failure such as disconnection between the two can be avoided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a tuning-fork type crystal vibrating piece according to an embodiment.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a view corresponding to FIG. 1 when the wraparound dimension of the electrode to the main surface is set large.
FIG. 4 is a diagram showing a simulation result when the position of the groove is displaced in the leg width direction.
FIG. 5 is a diagram showing a simulation result when the position of the in-groove electrode is displaced in the leg width direction.
FIG. 6 is a diagram showing a simulation result when both the position of the groove and the position of the electrode in the groove are displaced in the leg width direction.
FIG. 7 is a view corresponding to FIG. 1 in a modified example.
FIG. 8 is a diagram showing a simulation result in a modified example.
FIG. 9 is a view corresponding to FIG. 1 in a conventional example.
[Explanation of symbols]
1 Tuning fork type resonator element
11, 12 legs
11a, 12a Main surface
11b, 12b side
11c, 12c groove
13a, 14a Groove electrode
13b, 14b Side electrode

Claims (6)

A plurality of legs are provided, a groove is formed on the main surface of each leg, an in-groove electrode is formed inside the groove, and a side electrode is formed on the side of the leg. In the tuning fork type resonator element, in which the inner electrode and the side electrode formed on the side surface located on the inner side among the side surfaces of the other leg portions are connected by the routing electrode extending along the main surface ,
The distance from the center line passing through the vibration center point and extending along the extending direction of the leg portion to the center position in the width direction of the groove portion is set longer than the distance from the center line to the center position in the width direction of the leg portion. A tuning fork type vibration piece characterized by the above. A plurality of legs are provided, a groove is formed on the main surface of each leg, an in-groove electrode is formed inside the groove, and a side electrode is formed on the side of the leg. In the tuning fork type resonator element, in which the inner electrode and the side electrode formed on the side surface located on the inner side among the side surfaces of the other leg portions are connected by the routing electrode extending along the main surface ,
The distance from the center line passing through the vibration center point and extending along the extending direction of the leg portion to the center position in the width direction of the electrode in the groove is set to be longer than the distance from the center line to the center position in the width direction of the leg portion. A tuning-fork type vibrating piece characterized by A plurality of legs are provided, a groove is formed on the main surface of each leg, an in-groove electrode is formed inside the groove, and a side electrode is formed on the side of the leg. In the tuning fork type resonator element, in which the inner electrode and the side electrode formed on the side surface located on the inner side among the side surfaces of the other leg portions are connected by the routing electrode extending along the main surface ,
The distance from the center line passing through the center of vibration and extending along the extending direction of the leg to the center position in the width direction of the groove and the distance from the center line to the center position in the width direction of the electrode in the groove are A tuning fork-type vibrating piece characterized in that both are set to be longer than the distance to the center position in the width direction of the part. In the tuning fork type resonator element according to any one of claims 1 to 3,
The tuning fork type resonator element is characterized in that the shape of the groove formed in each main surface is formed symmetrically with respect to a center line extending through the center of vibration and extending in the extending direction of the leg. . In the tuning fork type vibrating piece according to any one of claims 1 to 4,
The tuning fork is characterized in that the shape of the in-groove electrode formed in each groove is symmetrical with respect to the center line passing through the center of vibration and extending along the extending direction of the leg. Type vibrating piece.   A tuning fork type crystal resonator element comprising the tuning fork type resonator element according to any one of claims 1 to 5, wherein the tuning fork type crystal element is mounted in a package.

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